Ann Severson, 16, stayed with her father through a summer aboard the Mermaid, his fishing vessel, to please him and lend what support she could since he was badly crippled with rheumatism. But after life with a wealthy aunt in Philadelphia, the routine aboard ship with her brother, Carl, who resented her bitterly, seemed rough and uncomfortable. The boy wanted a chance to attend college. In time Ann found the realization that she was needed by her father and brother a compelling reason to remain in Seattle, seeing that her father underwent therapy and helping Carl with the program of study which the family's joint efforts helped to assure. A readable story of a girl cultivating selflessness against a credible background. All comes right when Don McDermott, the boy she left behind decides at summer's end that the following year he too will sign on board the Mermaid.